in America, the vaccine is referred to as the "Pfizer vaccine" in the majority of newsletters. I understand this varies based on what country you're in, but this isn't unique there and is common practice for this vaccine's name.
Pfizer is easier to type than "Pfizer BioNTech" (there's 3 capital letters in that second word, 2 next to each other).
"The process is the vaccine" aka manufacturing the vaccine is the hardest part. Saying that Pfizer is just a partner of the "real" vaccine developer downplays the importance of manufacturing to a significant degree. It's just as much Pfizer's vaccine as it is BioNTech's.
It's still a bit unfortunate that this vaccine gets marketed as the sole achievement of a major us company while in reality the larger part of the funding for its development came from other parties, the single most biggest being german tax-payers.
Pfizer is easier to type than "Pfizer BioNTech" (there's 3 capital letters in that second word, 2 next to each other).
Laziness wins.